1. Field of the Invention
The present invention relates to thin-film transistors, and more particularly, to methods for producing thin-film transistors under low temperatures.
2. Description of Related Art
Transparent electronics is one of the crucial technologies for the next generation of optoelectronic devices, such as displays, photovoltaics, and home electronic appliances. Particularly, transparent thin-film transistors (TTFTs) are key devices for realizing these transparent electronic products. Oxide wide band-gap semiconductors have been proposed as the active channel in the TTFTs. Among them, zinc oxide (ZnO) is an ideal material to produce the active channel because of its low photosensitivity, low cost, simple processing method, especially high mobility, and lack of environmental concerns.
In addition, conventional transparent thin-film transistors are usually “bottom gate” type, having a gate dielectric layer that is typically inorganic. Taking the zinc oxide semiconductor TFT as an example, its manufacturing method may comprise coating a sol-gel solution of zinc oxide on an inorganic dielectric layer, removing the solvent of the sol-gel solution by a conventional thermal process thus obtaining a gel, and annealing the gel with a high temperature to grow and form the zinc oxide semiconductor layer. Although the thin-film transistor produced by the above sol-gel method may have acceptable properties, its processing temperature is typically more than 500° C., resulting in high manufacturing cost, low yield, and restricted selection of materials to produce the substrate and the gate dielectric layer.
Accordingly, it would be advantageous to provide a novel thin-film transistor and forming method for resolving the above problems of the prior art.